Time interleaved systems, such as a time interleaved analog-to-digital converter (ADC), are generally sensitive to noise at the interleaving frequency or at harmonics of the interleaving frequency. Such noise tends to destroy matching of the interleaved circuits in both the amplitude and time domains. Removal of noise at the interleaving frequency or at harmonics of the interleaving frequency therefore improves performance of the time interleaved systems.
Conventional noise removal techniques employ a digital subharmonic filter, for example, at the output of the time interleaved system. The digital subharmonic filter attempts to remove the effects of subharmonic noise from the conversion product. However, subharmonic filters are expensive in terms of power and silicon area.